Air-brake system.



J. HUGHES. AIR BRAKE SYSTEM.

APPLICATION FILED MAY 27, 1908.

Patented Apr. 20, 1909.

INVENTOR UNITED .srnras rAtrENr OFFICE i roan marita -dilutes. memoir I ta ting-mm.-

no. 913 ove.

' 7 Letteri Patent.

Application as, :1, 190a. 8omlHo.436,'8 19.

v such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvementsoin air brake s stems, adapted for use in connection with t e systems now employed and applicable to mountain travel as well as general conditions. i

One object is the provision of means for automatically maintaming the auxiliary reservoir on each car charged at all times.

Another object is the provision of means whereby the full pressure from the main reservoir may be applied to the brake cylinder. As a result a higher brake pressure is afforded than is now obtainable} Still another object is the provision of. means whereby the valve controlling the communication between the auxiliary reservoir and the brake cylinder is made more sensitive to reductions of pressure in the main train line.

A further object is the separation of the brake operating pressure and the pressure operating the valve. f 11 v V i A still further and highly important object is the provision of means whereby the auxiliary reservoir is recharged while and during the time when the brakes are set.

whereby the brakes remain set 1n an emergency application until the engineer moves his valve to running position, even though there may be a leakin the line.

A still further object is the saving of wear and tear on the air pump.

Another object is the provision of means whereby the valve may be caused to operat? osso several times in succession without the any a preciable amount .of air.

Stil another object is that the, use of retrainers now generally employed to retain a small viated. a

.. A further objectis the provision of means whereby the pressure in the main train line is reduced thereb avoiding the usual strain on the hose and't e consequent reduction of the liability of leakage,

To these and other ends therefore, my invention consists in certain novel features and combinations such as will bemore full described hereinafter and particularly pointed out in the claims.

In the accompanying drawings; Figure 1 is a plan view illustrating one arrangement embodying my invention.

As is well known the present air brake system is defective in that the engineer cannot make an emergency application of the brakes immediately after having released the brakes because of the loss of air and the conse uent reduction of ressure in the several auxl 'ary reservoirs. lso inexperienced engineers are very liable to waste the air in making service applications of the brakes so that it requires considerable work on the art of the air pump to recharge the auxiliary reservoirs. Furthermore, in all systems with which I am familiar it is absolutely impossible for the air pum to rechar e the auxlliary reservoirs during t e time w en the brakes Iate'nted 49 1 so, not;

pressure in the brake cylinders, is ob-- are applied or set. Again, the valve mechwill be understood that when adjusting the brake system to the cars, the brakes are so hung that the pressure exerted against the wheels is-sufliclent to retard and etc the movement of the car when empty. This adjustment of the brakes to an empty car is made because if the brakes were a plied too strongly they would look the w leels and cause the empty car to slide, flattenin the wheels and operating on slippery ral s to accelerate rather than retard the progress of the car. power it is obvious that in mountain travel particularly, great danger cannot be avoided especially when it is considered that a freight train may consist of from fifty to ninety ormore cars. l My inventlon is designed to overcome the foregoing dlsadvantages by supplymg means In view of such loss 1n brakin as is a plied to a loade train line (as is required in mountain travel) leaks are very apt to develop especially in the hose connecting adjacent cars and should such' leakage occur, the brakes wilhbe applied or creep on when the engineer does not wish to slow down or step. In my invention, the liability of leakage in the main train line is very much reduced because it is only necessary to carry a comparatively low pressure therein. I

Another fruitful source of complalnt is that in a long main train, the reduction of air in the train line to make a service application for instance, will not be felt at the rear end of the train. That is to say, the re-" duction of pressure at such rear end will be so slight as to fail to o erate the valve and hence the momentum o the rear cars will not be aiiected and their weight will 'ress against the forward cars rendering it di cult to stop.

the train. It is also of fre uent occurrence that a small leak at any point etween the auxiliary reservoir and the brake cylinder when the brakes are set, will permit the air to leak out of the brake cylinder and release the brakes on that car. This occurrence is rendered absolutely impossible'in my invention as leakage of air cannot affect the set of thebrakes when a heavy application of the air pressure is made. In the brake systems now in common use the pump cannot re-- charge the auxiliary reservoirs while the brakes are set because the auxiliary reservoirs are connected to the train line throu h the valves. This renders it necessary for t e pumps to work very rapidly after the brakes are released in order to ring the pressure up to the required degreeassoon as possible. My invention reduces the wear and tear and strain on the pumps because the latter may be recharging the auxiliary reservoirs while the brakes are set.

Referring now to the drawings, A indicates" an auxiliary train line 6 in communication at all times with the main reservoir and unafiected b the operation of the engineers valve, suc auxiliary train line being combined with cooperating features also forming a art of my invention.

eturning to the main train line 2, such line extends the length of the train in the usual manner, the sections on adjacent cars being coupled together by hose connections 7. An auxiliary reservoir 8 such as is carried by each car is directly connected to the main train line 2- by a branch pi e 9 in which is located a out 01f cook 10 and a valve 11 adapted to permit the air to enter the auxiliar vmanner, such rod being encircled by a spring 15 normally tending to retain the brake cylinder piston at its inner limit of movement, and the brakes released.

Interposed in the connection between the auxiliary reservoir and the brake cylinder is a valve chamber 16 closed at each end and containing a valve 17 provided with a port 18 adapted to register with and connect the pipes 19 and 20 leading from the auxiliary reservoir and to the tively.

Communication through the pipes 19 and 20 is normally closed when the engineer's valve is in running osition. The pi es are connected to the va ve chamber, and in order to retain the valve on its seat and compensate for wear provide a spring 21 interposed between the valve and the wall of the chamber. Other valve constructions may be used in place of that shown.

The valve chamber is provided with an exhaust opening 22 leading preferably to the atmosphere. An exhaust port 23 formed in the valve normally affords communication between the brake cylinder pipe 20 and the exhaust port 22 ,,when the engineers valve is in running position to permit air in the brake cylinder to exhaust to the atmos here and release -the brakes. This norma position of the exhaust port also prevents the possibilit of the brakes creepin on in case of a leaf; around the valve shou d one occur The valve is-equip ed with a stem 24 passing through one en of the valve chamber and connected with a iston 25 in the piston chamber 26. It must be borne in mind that there is absolutely no communication for air between the piston chamber and the valve chamber. A spring 27 encircles the valve stem 24 Within the piston chamber and behind the piston 25.

A graduating stem 28 .is seated in that en of the piston chamber op osite the piston 25, such stem being yielding y supported in extended position by a spring 29, and adapted brake cylinder respec- "to be engaged by the pistoii when an eiiielfgency a plication of the brakes is made.

' The gra uating stern at its outer end may the spring 29, S r the end of the grad ii and compressed by the piston 25 du fig" bod'ying theinventi ii;

e'rate the piston when the. pressure in main train line isreduced, I provide an sit tight piston auxiliary reservoir coniinun i'catiqn wgth the piston chamber on that side of the piston 25 opposite the graduating stemy and. as oiie mean's forrsuppllying the. 'provi d'e m I pro'vide 1-; is pi chambei with equaliz'ing groove 01' port 33 which in; the

present instance, is located adjacent that end "of the chamber =w1'1erein the graduating valve issituated, the operation of which will beset forth in detail. The fin'sin tr in line 'is connected to the piston chamber 26 by a "iip'e '2. The auxiliary train line 6 extends throughout the length of the train in the same manner as. does the main, train line 2*, j

the sections being coupled by hose connections 34.

"A branch pipe 35 connects each auxiliary reservoir directly with the faux'iliary train line, such pipe having a cut off valve 36 and a check va ve 37 therein. The auxiliary train line is provided with a feed valve 38 adjacent the engineers valve which is adjusted to admit any predetermined pressure to the auxiliary train line. It will be seen from the -drawing that the normal function of the mainline is'to supply air to the piston au xiliary reservoir an to reduce the air pressure in the iston chamber. Hence, acomparatively ow ressure may be carried in the main train ine with a consequentreduction in the liability of leakage. The auxiliar trainline, however, must sup 'ly the auxi iary reservoirs with air at bra ing pressure, say 80 pounds or even higher on passenger trains, and hence the feed valve'38 must 'be set to allow the auxiliary train line to carry a higher pressure than the 'main train line. In order to provide for emergency application's, however, I arrange a by-pass 39 between the inain reservoir and the auxiliary train line, around the engineers valve and the feed 30 may be omitted in other constructions Bli'l: I i i'der as siipp'ly suificientpres'sfireto 0 :5,

ose'd by the piston in plic'atigi'n ofthe brakes is f vaiv, 38- such bye j biiig stationed a by-pass valve 40. it this means I iii; iii;

saintl threw the entire pressure iii tiie niiiiii carry a supplementary spring 3 0 1i hter than i g '30 eXten. s tey ngi ating stem to be engageg reservoir, say 110 pounds into each of the auxiliary reservoirs in the train, Both the 0 main and auxiliary train lines. are equipped v I p P u I with angl' books 41 to shut ofithe airoli the service application of thehraikesi, instead of compressing the main spring 29.] The spring last car 6 the train, in the usual manner.

Iii the present air-brake s stems", the air hose 'on the fast ear is allowe w han dea as .a t of which sand, dirt, gravel or other extraneous mite-a l fih'ds its ei iiii the hose imiwhen the car is a itiifl coupled in a train, such niate'ria is driven on hout the s stern and seriously. affehts thee 'ciency of t e valves as we1l-a'sclbg" 'ii' the line. t In i'ny invention, the free thu s 0% the air liose For the I'Iiain' and aux liary may hecoupid to g'ethertherehy'preventin the entrance? of ei'ctraneous material as wei as retaining the free ends ofjthe h'os'e above the road bed out-of danger o f injury. v-

The operation of m i ventio as follows: Assume that the train is moving and of the brakes will move his v'a'lve to service position which novement oithe valve cuts off the I coinmumcation between the rn'am reservolrand themam train l1ne2 and o ens the main train line to the atmosphere.

t rough a port 43 in the engineers valve, thus, allowing some of the air in the main train line to exhaust into the atnios li'ere'. The exhaust of air into the atmos' ere reduces the pressure in the mainjtrain ine, therehy"e rhitting the then higher pressure ineacho the air tight pisto'n auxiliary reservoirs 31 to force the istons 25 in the piston'chan bersagainst the ightsp'rings 30 carried by the grarljuating steins 28. The rfiovenientof the pistons is communicated to the'valves 17 ,drawing the latter along in their chambers until the valve ports 18 register with and connect the open ends of the pipes l-Qand 2Q therebyfa'dmitting air from the auxiliary reservoirs 8, into the brake c linders 12, the pressure of operating-to set the "brakes. Meanwhile the engagement 'n ,25 with the light v springs '30 erates to compress the latter and permit t e pistons 25 to uncover the bypass erl ualizin'g ports 33 allowing the higher pressu ein the piston suxihaiyreserv r to pass around the pistons 25fa'1'1d equalize "with the 'reducedfpre'ssiire in the main train line.

iary reservoirs.

" tons away from the ports 33 and thus prefrom the piston auxilvents further leaka e ii? equalization of air a pressure consumes but very little time because the air in the piston auxiliary reservoirs has to fill the space above the pistons when the latter are moved to their outward ositions and the piston auxiliary reservoirs ibse but little air in the process. On the other hand, when the pistons 25 are moved back to normal position, the air isforced back into the piston auxiliary reservoirs thereby raising their pressure. The backward thrusts imparted to the pistons 25 by the springs 30 operate to move the valves back to prevent communication between the pipes 19 and 20 by moving the ports 18 out of register with the pipes 20 thus locking the pressure in the bra e cylinders. The communication afforded by the valve between the auxiliary reservoir and the brake cylinder during a service application is maintained for a limited time only, because the comparatively small reduction in main train line pressure will quickly permit the equalization around the piston between the piston auxiliary reservoir and the main train line, thereby allowing the spring 30 to return the piston to lap position, which movement of the piston will return the valve to lap position to lockthe pressure in the brake cylinder and prevent the further admission of pressure thereto. The engineer watching his I air gage, observes that sufiicient air, say 5 pounds, has been allowed to escape from the main train line whereupon he moves the valve 4, to lap position (providing he wishes to hold the brakes set and make a full stop). When the engineer's valve is in lap position no air can escape from the main train line nor can any air enter the main train line from the main reservoir A.

When the engineer desires to release the brakes without making a full stop he moves his valve from service to running position at which time the exhaust of air from the main train line ceases and the main reservoir is placed in communication with the main train line to raise the pressure therein to the predetermined point at which the feed valve 5 is set. The entrance of air into the main train line when the engineers valve is returned to running position, raises the pressure in the main train line to a point above the pressure furnished by the piston auxiliary reservoirs behind the pistons 25. Consequently, the pistons are forced back to their normal inward positions and communicate motion to the respective valves which are likewise returned to normal position bringing the exhaust ports 23 into register with the brake cylinder pipes 20 and exhaust openings 22 to permit the air in the brake cylinders to esca e, whereupon the springs 15 return the bra e cylinder pistons to their inner positions to release the brakes. The ressure of the air in. the main train line orces the pistons 25 backward until the supply ports 32 in the iston chambers are uncovered to permit t e higher ressure of the main train ine to equalize wit the pressure in the piston auxiliary reservoirs, thereby replenishing the latter. The movement of the pistons 25 to such position as to uncover the supply ports 32 causes the pistons to compress the springs 27 so that when the ressure on both sides of the pistons equa 'zes, the springs force the pistons forward j ustfar enough to clear the supply ports and prevent communication between the piston auxiliar reservoirs and the main train line. The a vantage of this arrangementis that it makes the pistons more sensitive to reductions of pressure in the main train line. In long trains the ordinary reduction of pressure in the main train line is not sufiicient on the rear cars to cause the operation of the istons. In my construction, should the supp y ports 32 be normally open, the air in the piston auxiliary reservoirs would leak through the ports without operating the pistons under the-same conditions. But by closing said supply ports any reduction of pressure in the main train line will cause the pistons 25 on the rear cars of a long train to be 0 erated. The opening of communication etween the pipes 19 and 20 when the brakes are to be set permits a portion of the air in the auxiliary reservoirs 8 to exhaust into the brake c linglers- 12 thereby reducing thepressure in the auxiliary reservoirs and in the auxiliary train line which, it will be remembered, is always in communication with the main reservoir. The consequent reduction of pressure in the main reservoir at once sets the air pump to working and the air in the main reservoir and consequently in the auxiliary train line and the auxiliary reservoirs is brought up to the required pressure while the brakes are set. Thls is impossible in all prior constructions with which I am familiar because the air is admitted to the auxiliary reservoirs through the triple valves whereas in my invention there is a complete separation of the air used for braking pressure and the air used to operate the valves, nor does the air for supplying the auxiliary reservoirs 8 pass through the valves. The most important advantage is that the auxiliary reservoirs are always charged with air so that at any time the engineer can set the brakes, even immediately after having released the air from the revious stop. Another advantage is that t 1e retainers now in general use to hold a low pressure in the brake cylinders are not necessary. These retainers are a great source of trouble. They frequently become clogged thereby retaining a considerable pressure in the brake cylinders and rendering it impossible to fully release the brakes. Furthermore, inexperi: enced train hands hearing the sound of escaping air therefrom think the mechanism is wrong and close or partially close the valves governing the amount of air to be carried in the brake cylinders, with the same result.

In my invention should the braking mechanism on one or more cars be out of order all that is necessary is to shut the cut off valves in the branch pipes 9 and 35 supplying the auxiliary reservoir 8 which does not affect the braking pressure on 'the other cars. Furthermore, in case of accident to the auxiliary train line all that is necessary is to shut oil' the air therefrom, the auxiliary reservoir 8 then being supplied from the branch pipes 9 leading from the main train line. In such .an event the feed valve 5 controlling the pressure in the main train line is adjusted to allow a higher pressurqtto be carried'therein because normally the main train line carries a lower pressure than the auxiliary train line. Another great advantage residing in my construction is that in a heavy or an emergency application of the brakes the brake cylinder is kept filled with air even though it may leak, because the pump is constantly forcing air directly into the auxiliary reservoirs the moment the pressure in the main reservoir decreases.

In making an emergency or a heavy application of the brakes, the engineer will throw the valve 4 to its farthest limit of movement opening the exhaust ort 43 to its widest )ossible extent and c osing communication etween the main reservoir pipe 3 and the main train line 2. The sudden reduction in pressure in the main train line causes the pressure in the piston auxiliary reservoirs to act with rapidity. The pistons 25 are forcibly driven against the graduating stems 28, depressing the latter against the tension not only of the light springs 30 if employed but also of the heavier springs 29. This movement of the pistons carries them ast the equalizing ports 33 so that no air rom the piston auxiliary reservoirs can leak around into the train line. Simultaneously with the movement of the pistons, the valves are moved so that the auxiliary reservoirs 8 are in communication with the brake cylinder ipes. If the occasion seems to demand it, t to engineer may also open the controlling cock 40 in the by-pass 39leading from themain reservoir directly to the auxiliary train line aroupd'the feed valve 38 thereby throwing the entire pressure of the main reservoir into the auxiliary reservoirs 8 and brake cylinders. The air, pump 1 commences to pump air into the main reservoir as soon as the ressure therein is reduced so that the pre etermined' full pressure is maintained even though leaks may occur. The valve controlling communication between the auxiliary reservoir and the brake cylinder will remain in its 0 en position during an emergency application, so long as the pressure above the piston is greater than the air pressure in the main train line assisted by the springs 29 and 30, but when the main train nne iressure is raised, the valve is returned to roease )osition.

The brake cylinders are equipped with any of the usual styles of reducers 42 to prevent the brakes from setting so hard against the wheels as to lock the latter and cause the car to slide. The brakes are released as hereinbefore described.

In making up a train, it is considered the better plan to' couple all empties at the rear end of the train because they do not require so great a brake ressure as the loaded cars. To insure that t e brakes shall be applied with less force on the empties in the rear I preferably couple a reducing valve similar to feed valves 5 and 38 between the em ty and loaded cars, such a reducing valve being of any convenient construction to permit 1t to be engaged by the adjacent hose cou lings in the auxiliary train line between tlie loaded and empty cars. When the train is made u with oaded and empty cars interposed, t e train hands can turn the cut off cocks 37 in the branch pipes 35 thus permitting the auxiliary reservoirs 8 of the empty cars to be supplied from the low pressure or main train line 2, only.

A great practical advantage attained by the use of my invention may be illustrated as follows: Assume that a train of mixed loaded and cm ty cars is equipped with my invention. he auxiliary tram line is charged to 1 00 pounds pressure and the main train line to 70 pounds. The auxiliary reservoirs of the empty cars are supplied with air from the mam train line onl consequently the auxiliary reservoirs on t to empty cars are charged to 70 pounds and the auxiliary reservoirs on the loaded cars to 100 pounds. It will be understood that the admission of 20 pounds of air from the large auxiliary reservoir-into the smaller brake cylinder creates a braking pressure of 50 ounds. In traveling down steep grades, it IS necessary to utilize every pound of brake pressure possible, especially on heavy trains. Now, in my invention, a 20 ounds reduction in the main train line wil permit 20 pounds of air from the auxiliary reservoirs of the empty and loaded cars to enter the brake cylinders. This pressure on the empty cars will equalize into the brake cylinders at 50 pounds because of the smaller area of the brake cylinders. The admission of 20 pounds of air from the auxiliary reservoirs of the loaded cars into the brake cylinders will leave apressure of 80 pounds in the auxiliary reservoir of such loaded cars. This pressure is raised by the entrance of air from the auxiliary train line to 100pounds again. In order of pressure enterrng the brake cylinder from If restricted, the triple valve wil remain to utilize the ressure stored in the auxiliary reservoirs of t e loaded cars, it is possible in my invention to make a further reduction of pressure in the main train hne which will cause the valves on the loaded cars to open, admitting further braking pressure to the brake cylinders of such loaded cars, it being obvious that the pressure in the brake cylinders can be raised to equalize with the pressure in the auxiliary train line. Thus, after the brakes are once set, as by a reduction of 20 pounds, a sudden further reduction in the pressure in the main train line of 10 pounds will cause the valves to move rapidly past'the equalizing ports 33 and mainta n the commumcation open between the auxiliary reservoirs and brake cylinders of all the cars. This will not injure the train as the brakes have already been set and the slack taken out.

In present air brake systems wherein the pressure of air is equalized 1n the auxiliary reservoirs and in the train lines, a reduction of 10 pounds in the train line results in the ad mission of 10 ounds from the auxiliary reservoir to the bra eeylinder and the size of the cornmunication between the auxiliary reservoir and the brake cylinder is of no im ortanee.

in open position a longer time than if the communicating opening is large, but only ten pounds of air will enter the brake cylinder 1n any event. In my invention, the size of the equalizing port 33 controls the amount the auxiliary reservoir and a ten ound reduction in the main train .line wit 1 a small equalizing port through which the air on opposite sides of the piston would equalize slowly, might allow 100 pounds of airto enter the brake cylinder.

My invention can be applied to any of the well known braking systems now in use with but a minimum of trouble and expense. It Will be observed that the piston auxiliary reservoir might be dispensed with by making the piston chamber longer, its only function being to contain suflicient air to operate the piston a number of times successively without recharging. Also other changes might be made in the form and arrangement of the several parts described without departing from the spirit and scope of my invention.

The equalization of the braking pressure throughout the entire train is of great imortance. In the systems now in use, the

rake, pistons have what is termed long or short travel, that is, the brake cylinder piston of one car may move seven inches to apply the brakes or it may have to be moved a distance of eleven inches. The brake pistons on the several cars may have various lengths of travel. The auxiliary reservoirs are all charged with say 80 pounds of air, irrespective of the length of travel of the brake v necessarg pistons. N ow when the valve is operated to open communication between the auxiliary reservoir and the brake cylinder, the air in the former rushes into the cylinder and e ualizes with the pressure of air in the auxi iary reservoir. Thus if the brake cylinder piston must move seven inches-the braking pressure is' higher than in a cylinder wherein the piston must move eleven inches to apply the brakes.

In my invention owing to the fact that the main reservoir is in constant communication with the auxiliary reservoirs, up to eighty pounds, the moment the ressure in the auxiliary reservoirs drops be ow eighty pounds, the feed valve 38 opens to admit air to the auxiliary train line and consequently the pressure of air is raised to eighty ounds in the auxiliary reservoirs and in the rake cylinder as well. Hence it will be seen that I obtain a much higher braking pressure than is now obtainable, which hi her braking pressure offsets the loss occasioned by the displacement of the brakes on a loaded car.

A very important advanta e of m invention may be explained as foliows: ormerly in trains where the loaded ears are in front and the empties are behind, the reduction of pressure in the main train line to cause a service application of the brakes will cause the air to equalize in the auxiliary reservoirs and brake cylinders of the empties at a high pressure, say 50 pounds, because,

owing to the manner of hanging the brakes, the brake pistons on the empty cars do not have so far to travel before applying the brakes as do the brake pistons on the loaded cars. On the loaded cars, the reduction of] pressure in the main train line will cause the air in the auxiliary reservoir to equalize in both the brake cylinder and auxiliary reservoirs at a pressure of, say 45 ounds on a 100,000 capacity car, because t 1e weight of the car has displaced the brake mechanism relative to the wheels. It is obvious therefore, that although a single reduction of pressure in the main train line may have een made, there is less braking pressure on the loaded cars than on the empty cars and it is necessary therefore, when releasing the brakes, to raise the pressure in the valves on the rear empty cars higher than will be in the valves on the forward loaded ears ecause the counter balancing pressure on the forward loaded cars need not be as great. In the present example, the pressure must be raised in the main train line from 45 pounds to 51 pounds andover before the brakes on the empty cars will be released, but the increase of pressure in the main train line above 45 pounds will release the brakes on the forward loaded cars. Furthermore, as soon as the brakes on the forward loaded cars are released, the auxiliary reservoirs on those cars (in former air brake systems) will at once grab or accumulatethe air in the main train linc, thereby preventing it from traveling back to the empty rear cars .until the auxiliary resermust sometimes ho d his train or min-- utes before starting ahead in order to permit the pressure in theirain line to increase empty cars; Should, he start ahead before the brakes on the'empty cars are released,

he will very likely pull h1s train apart owing devices have been invented in an at empt to automatically re 'ulate the brake pressure through the di erenoegin the load, such meanshave been ineflicient to thoroughly meet all conditions; I

In my invention, the. air in the auxiliary reservoir on the loaded cars is at a higher pressure (say 110 pounds) than in the empty cars,- wherein the pressure is at, say .70 pounds.

empty cars in the auxiliary train line.

Now, although applying the brakes, the

pistons in the brake cylinders on the loaded oars must travel farther than those on the empty cars, the higher. pressure in the am:- iliary reservoirs on .the loaded-cars admits a greater amount of air to the brake cylinders of the loaded cars than will be admitted to the brake cylinders of the. empty cars.- The equalization of the higher pressure carried by theloaded cars in the brake cylinders and auxiliary reservoirs will ofiset the additional le'n th of travel required on the loaded cars and hence, the braking pressure will be equalized throughout the train. Heretofore, the brakes on the empty cars are the first to be set and the last to release.

The ideal condition is to apply the brakes: simultaneously or release the brakes simul-- piston chambers of .the empty cars to reease the brakes. The aux iaryreservoirs on theloaded cars in front cannot robthe main train line of air because, owing to theprovision of the auxiliary train line,the auxihary reservoirs have been recharged and the pressure in such auxiliary jreservoir is higher than in the mam tram line; The pressure in the main train lineis in efiecte ualized' throughout the length of thef'train "ecau'se' the main" train no connection with the; piston 'auxilia spectively. It w' switching cars one or more may be kicked This is owing to the inte osition of the feed valve between the 1011 ed and the brakepressurelinen This separation of thevalve controllingair pressure from the brake pressureconstitutes, the .main idea of my invention and by so isolating these two air pressuresfl am able tojwork the brakes automatically first and after by'actu-atin'g the by-pass valve 40 ,to introduce stra' ht air pressure directly into the brake cyin- .ders'thro'ugh the auxiliary reservoir. Forsufiiciently to release the brakes on the [straight air brake too.

, Another feature ofimy-invention resides in the provision of, bleeding cocks 44 and 44 on and brake cylinder rebe understood that in onto a side track, the angle cocks 41 having been closed and the hose connectionsdisengaged 'priorto the switching o eration, thus locking the air pressure in t e train lines and auxlliary reservoirs on the cars so switched. v The brakeman instead of climbing on the side tracked carsto set the hand brakes will turn the angle cocks to reducethe press'urein the train line and set the brakes t is some times inconvenient tocouple onto the side tracked carsso, that when it is desired to release'thebrakes, a bleedin cock onthe auxiliary reservoir is o ened thereby reducing the pressure in the rake cylinder providing communication between the brake cylinder and auxiliary reservoir ifsv 0 en. If Y it is closed, and there is notenoug air to makean emergency application, nothing is left but to con le on and recharge the main train line tore ease the brakes. In my in- .vention under the same conditions, the

brakeman merely has to operate the bleeding cock 44.01). the piston auxiliary providi aservice application has been made, wh-i dl l operation w permit the air in the main trainline to operate the valve and release the air in the brake cylinder. If the pressure in the main train line is. too low, however, the ,brakeman can then operate the bleeding cook 44 on the brake cyllnder to release the air therefrom.

' Havin thus fully disclosed my invention, what I c aim as new is:

' 1. An air brake system comprising an auxiliary reservoir, a source of air under pressure directly connected thereto, a brake c linder,'-a valve chamber, "a valve in the chamber controlling the communication between the auxiliary reservoir and the brake cylinder and between the latter and theatmosphere, a piston chamber air tight relative to the valve chamber, a low pressure train vjline communicating with the piston chamber, a piston operating in the chamber, means for storingx'air on one side of the pisten, the pistoncham or provided with means for supplying air to the'storage means and for permitting the a ir in the storage means to equalize with the air in the; low ressure surein said train line.

2. An air'brake system having an auxiltrain'line, and meansfor controlling t 1e pres- 1 iary reservoir in direct communication with a with an auxiliary reservoir, a brake cylinder in communication therewith, and a valve mechanism interposed in the communication, of a train line communicating with and controlling the actuation of the valve mechf anism, a main'reservoir, an auxiliary train line directly connecting the main and auxiliary reservoirs, a feed valve in the auxiliary train line, a by-pass around the feed valve and a cock controlling the by-pass,

' 4. In an air brake system, the combination with a main reservoir, an auxiliary reservoir, a brake cylinder, a communication between the auxiliary reservoir and brake cylinder, and a valve mechanism interposed in such communication, of a train line communicating with the main reservoir and the valve mechanism, anengineers valve and a feed valve located-in the train line between the main reservoir and the valve mechanism, a constantly charged auxiliary train line in constant communication with the main reservoir and the auxiliary reservoir, a branch pipe connecting the first named train line with the auxiliary reservoir, and cut-off cocks controlling the communication between the main and auxiliary train lines and the auxiliary reservoir.

5. An air brake system having a main reservoir, an auxiliary reservoir, separate train lines leading from the main reservoir, branch pipes connecting the respective train lines directly with t e auxiliary reservoir, and a cut-off cock in at least one of the branch pipes.

6. An air brake system comprising an auxiliary reservoir, a brake c linder in communication therewith, a va've mechanism controlling such communication,- a main reservoir, means controlling the actuation of the valve mechanism, a constantly charged auxiliary train line independent of the valvecontrolljng means and in constant communication with the main and auxiliary reservoirs and normally containing less pressure than that in the main reservoir, and means for admitting the entire pressure the main reservoir to the auxiliary train line.

7. An air brake system comprising an equalization of pressure on opposite si es of tion is made-for retaining the equalizing port a covered.

8. A valve mechanism for air brake systems comprising a valve controlling communication between the auxiliary reservoir-and the brake cylinder, -a piston chamber, a piston in the chamber, the chamber provided with supply and equalizing ports spaced a art from each other, means connecting t e piston and valve, a source of air pressure connected with the piston chamer on one side of the piston, the supply port adapted. to equalize the pressure on 0th sides of the piston, means for causing the piston to close the supply port when'the pressure is equalized, means for reducing the pressure on one side of the piston whereby the air pressure behind causes it to uncover the equalizing port, and means for causing the piston to close the e ualizin port when the pressure on both si es of t e piston is again equalized.

9. A valve mechanism for air brake systems comprising a valve controlling communication between the auxiliary reservoir and the brake cylinder, a iston chamber, a piston in the piston cham er, means for introducing ressure to the'piston chamber on one side 0 the piston, a yieldingly-supported graduating stem, means connecting the valve and piston, the piston chamber provided with an equalizing port and a supply port, the latter adapted to equalize the pressure on both sides of the piston,a spring for causing the piston to normally close the supply port, means for reducing the ressure on one side of the piston to cause t e latter to uncover the equalizing ort, and means engaged by the piston when it uncovers the equalizing port for causing the valve to close such e ualizing port when the pressure on both si es of the piston is a ain e ualized.

10. A valve mechanism 501 air rake systems'comprising a valve controlling communication between the auxiliary reservoir and the brake cylinder, a piston chamber, a piston in the piston chamber, a source ,of pressure communicatin with the piston chamber on one side of t e piston, a storage chamber communicating with the piston chamber on the o posite side of said piston, the piston cham er provided with supply and. equalizin ports for permittin the ampere ing .the; latte to. close-t the ports. when 'the,

PIGSHIH'QziS equalized:

1 1.. Am: air.- 5 brake. systems comprising a; reservoir, .a.

reservoin-an. auxrlia brake cylinder, a valve-chain er, pipes lead+ ing-fromthe 'aux11i theexhaustsopeningm piston chamber, a: tomlocated. inithe; lston chamben-a va vet stemconnecting. t at valvefiand :PiSliQIL, a;

spring interposecl-betweentthe piston and one -end-.- ofiits chamber,- a eplston auxiliary reservoir communicating with the. piston; chamber on 50116, side :ofithe piston the. iston.

chamber provided with a supply port orbyq passing alraround the, iston: valve to-the P18150111 auxiliary reservoir When the brakes are firstreleased, a graduating stem projecting: into the piston; chamber, a spring sup-- porting the stem in extended position,.a sec-r 0nd sprin .seated on the stem and rojecting beyond t e outer end. thereof, t1e..pistonchamber rovidednwith an equalizing port train line communicating with the .mainereservo1r andwiththelston chamber, an engmeers :valve m the ow .pressuretraln hne,

an auxiliary train line in'constant communi--.

a :valve :inthe chamber a piston chamber, a

piston in the piston chamber, means! connect-. mgi-the valve and piston, a train lme vcommunicating with the piston'chamber on one side of the piston, a connection between the train line and the. auxiliary :reservoin-the piston chamber provided with supply .and

equalizing ports to permit the pressure'in the pistonchamber to equalize on. both sides of v the piston when the latter is at one-limit of its movement or is in its service position, and means for automatically =moving the piston to close the ports when the pressure is equalizeds 13. In an air brake system, the combination witha main reservoir, an auxiliary reservoir; a brake cylinder in communication therewith, anda valve controlling communication between the auxiliaryreservoir and fi5-the brakecylinrleryof a piston'chamber, a.-

any reservoir and from the. brake cylinder to the. chamber, the chamber adjacent t e graduatingstem, alowpressure.

pistoniinithezpistonchamben-ithe piston connected to the yalvaJa train line communicate. a ing. with. the 1 iston chamber, the apiston. chambenprovirlhd with means for e u the air. ressure-on;op .osite sides 0 thGrPiS-s-JO ton,;. an ableeding coo s onthat. side of. the; iston o positetthe train line, and on .the.--. rake cy der respectively.v

14. An ainbrake system comprisinga main; reservoir, amain tram line leadmg therefrom,

a brake cylinder, an auxiliary reservoir come mumcat ng e therewlth a ,-.valve controlling such.:.-communieation, a 1 iston. chamber, a piston-inthepistoncham er the piston con-a trollin the actuation of. the ,valve, the-main. 0 train. etcommunicating with the piston 2 chamber and. with the auxiliary reservoir re.. spectiyely;

' 15. Anairbrake system comprisinga main reservoinan auxiliary reservoin; a .brake. l-, 5 indcrin communication therewith, a ,-va vemechanism including a a. piston chamber and piston, for controlling such,- com1nunication,. means for conducting air under pressureto theauxiliary reservoir and to the, piston chamber on .onesideofsthe piston, andai storage reservoir. communicating with. ,the. piston chamber; ontheuopposi-te .side of ithQv piston,- the chamberprovided with .meansfor permitting communicationaround the piston When=thelatteris in, one .or-the other of two positions.

16. ,An airbrake systemhaving. anaux'ilT iary reservoir, a main reservoir, a constantly charged auxiliary train line directly connect- 1 00 ing t e auxilianyand mainreservoirs torecharge the former-during the a plication of. the brakes, a main trainline, an DIGHJISfiODW nesting-the main trainlinea'nd the auxiliary reservoir.

17. An airnbrake systemlhavingian auxilaiary reservoir, a constantly, chargedhigh pressure and aloWpressur'etrain llne sepa-, rate from-each other, anbrake. '-cylinder,.- a valve controlling the communication be 1 1.0 tween the auxiliary reservoir and. the brake:- cylinder, and a piston for o eratingthe valve, tl1e piston1actuatedtby tlie decrease-or increase .inpressure .in the. lowtpressure train line, the ain pressurebeing normally equals. 11 ized on opposite sidesof the piston.

18. An airbrake system comprising a main and an auxiliary reservoir, a-brake cylinder,- a-valve controlling the communicationwbe-r tween the auxiliary-reservoirand the brake, cylinder; an air. pressure-actuated: piston for 1 operating the. valve, the air ressure nor.-- mallyequalized 0n op ositesicihsof the-piss. ton,- a main train line: or normally maintain.- ing air pressure against-the. piston, a .pipe connecting the maintrain line andthe .auxlh ianyrreservoir, and separate means intcon-f stant communication with the resalevoir for maintainingpressure in and recharge ing the auxiliary reservoir.

' 65 each ot 19. An air brake system having an auxiliary reservoir, a brake cylinder, a valve mechanism controlling the communication between the auxiliary reservoir and the brake scylinder, a main reservoir, a low ressure train line for actuating the valve mec ianism,

and a second constantly charged high pressure train line separate from the first named train line and connecting the auxiliary reservoir directly with the main reservoir at all times.

20. An air brake system comprising a brake cylinder, an auxiliary reservoir, a constantly open connection between the auxiliary reservoir and a source of compressed air,

a slide valve for opening and closing communication between the auxiliary reservoir and the brake cylinder and between the latter and the atmosphere, a iston chamber, a pis- -2 ton in the chamber a apted to actuate the valve, and a train line leading to the iston chamber, the piston chamber provide w1th means for permitting the air pressure to equalize around the piston. 21. An air brake system comprising an auxiliary reservoir, a main reservoir directly connected thereto, a brake cylinder, a valve controlling communication between the auxiliary reservoir and the brake cylinder, a piston chamber, a low ressure train line communicating therewith, a piston in the chamber, means for storing air on that side of the piston opposite the communication with the ow pressure train line, the piston chamber 3 provlded with means for normally equalizing the pressure of air on opposite sides of the piston, and means for controlling the pressure in said train line. v

22. An air brake system comprising an 40' auxiliary reservoir in direct communication with a source of air under pressure, a piston chamber closed against the supply of air to the auxiliary reservoir, a pistonin the chamber, a piston auxiliary reservoir on one side of the piston and adapted to contain air under pressure, a train line communicating with the piston chamber on the opposite side of the piston, the chamber permitting an equa ization of air pressures on opposite sides of the piston when the latter is at one limit of its movement.

23. An air brake system comprising an auxiliary reservoir, a brake cylinder, a valve chamber with which the auxiliary reservoir and the brake cylinder communicate, a valve in the chamber controlling the communication between the auxiliary reservoir and the brake cylinder, a constantly charged high pressure train line in direct communication with the auxiliar reservoir, a piston chamber, a iston in tlie chamber connected with the Va ve, a low pressure train line communicating with the piston chamber, and a web dividin the piston and valve chambers from rovided with means for 24. An air brake system having an auxiliary reservoir, a constantly charged high ressure and a low ressure train line separate rom each other, t e high pressure train line in constant communication with the auxiliary reservoir, and a valve mechanism with which the low pressure train line communicates, the fluctuation in pressure in the low pressure train line operating to actuate the valve mechanism controlling communication between the auxiliary reservoir and the brake cylinder.

25. An air brake system comprising a main and an auxiliary reservoir, a brake cylinder, a valve controlling communication between the auxiliary reservoir and the brake c linder, a piston chamber, a piston in the piston chamber, the piston connected to the valve, a main train line communicatin with the pis ton chamber on one side of t e piston, the piston chamber having a by-pass controlled y the piston for admitting pressure to the opposite side of the piston to maintain the brakes released normally, the variation in pressure in the train line constitutin the means actuating the valve, and means independent of the main train line and in constant communication with the main reservoir for maintaining pressure in and automatic- .ally recharging the auxiliary reservoir as soon as the pressure therein is reduced.

26. An air brake system having an auxiliary reservoir in direct communication with a source of air under pressure, a piston chamber, a train line communicating with the piston chamber, the latter closed against the supply of air to the auxiliary reservoir, a piston operating in the chamber, a piston auxiliary reservoir independent of the auxiliary reservoir and containing air under pressure on one side of the iston, the train line communicating with tlie piston chamber on the other side of the piston and separated from the communication between the auxiliary-- reservoir and the source of compressed air, and means controlling the pressure of air in the main train line.

27. An air brake system comprising a main reservoir, an auxiliary reservoir, a brake cylinder, a high pressure train line leading from the main reservoir directly to the auxiliary reservoir, a valve controlling communication between the auxiliary reservoir and the brake cylinder, a piston chamber, a piston in the chamber, the piston connected to the valve, and a low pressure train line communicating with the piston chamber and adapted to var the pressure therein to positively actuate t e va ve by air pressure in either direction.

28. An air brake system comprising a main reservoir, an auxiliary reservoir, a brake cylinder connected to the auxiliary reservoir, a valve controlling such connection, a high pressure train line connecting the main and ton in t e chamber, the piston connects to auxilia reservoirs,a piston chamber, a isadmitting air from the low pressure train 10 line to the piston auxiliary reservoir.

the valve, a low pressure train line commu- In testimony whereof, I aflix my signature nicaiting with the piston chamber on one side in presence of two witnesses.

o t e iston a iston auxih' 'ary reservoir indepentient of t e auxiliary reservoir and JOHN HUGHES communicat' with the piston chamber on Witnesses:

the opposite side of the valve, the chamber RALPH S. WARFIELD, having a by-pass controlledvby the piston for NELLIE M. Amos. 

